Synthesis of new halo-substituted quinolinecarboxaldehyde-hydrazone derivatives, structural illuminations, investigation of effects on acetylcholinesterase activity and molecular modeling studies

Acetylcholinesterase (AChE) is a key serum esterase with antiatherosclerotic effects by preventing lipid peroxide oxidation. AChE inhibitors also serve as therapeutic targets for Alzheimer's disease. Newly developed halo-substituted quinolinecarboxaldehyde-hydrazone derivatives (1a–1 s) show significant pharmacological potential due to their broad biological activities. This study evaluated the inhibitory effects of halo-substituted quinolinecarboxaldehyde-hydrazone derivatives on AChE. Acetylcholine esterase IC₅₀ values ranged from 0.143 to 2.015 µM, and Kᵢ values from 0.078 ± 0.030 to 1.074 ± 0.105 µM. Tacrine served as the positive control. Molecular docking studies revealed that compounds 1b and 1k displayed pi-pi interactions (pi-alkyl, pi-pi stacking) and conventional hydrogen bonding. The molecular dynamics simulation study disclosed that compounds 1b and 1k formed stable complexes with the enzyme structure. Moreover, the density functional theory study demonstrated that the active compounds had similar electrical property and reactivity. Together with this, compound 1e was anticipated to exhibit the highest chemical stability among the compounds investigated. All of the compounds were shown to have a high absorption from the gastrointestinal tract and to meet Lipinski's criterion in SwissADME. As a result, it was determined that new halo-substituted quinoline carboxaldehyde-hydrazone derivatives showed strong inhibition effect on this enzyme. In comparison to the reference chemical Tacrine, 1k had the most potent inhibitory activity against AChE. In this context, we anticipate that the findings of this study will aid in identifying the adverse effects of both existing and novel quinolinecarboxaldehyde-hydrazone-based pharmaceutical drugs under development. Additionally, it should be effective in the production of novel AChE inhibitors. © 2025 Elsevier B.V.